It  Pays  to  Build  with  Concrete 

True  building  economy  is  realized  in  concrete-cobblestone 
construction.  Permanence  and  freedom  from  maintenance 
expense  make  its  first  cost  the  only  cost.  Thus  it  is  cheapest 
in  the  end.  Often  first  cost  will  be  lowest  because  the  owner 
can  do  much  of  the  work  himself  during  spare  time  or  with 
hired  help.  Sand,  pebbles  and  stone  used  for  the  walls  can 
be  obtained  locally  for  the  mere  cost  of  hauling. 

The  storm-proof  and  fire-resistive  qualities  of  cobblestone 
construction  make  it  especially  desirable.  So  great  is  the 
strength  of  buildings  constructed  of  this  material  that  the 
most  severe  tornadoes  seldom  damage  them.  Concrete  and 
stone  likewise  has  no  superior  as  a  fireproof  material.  Since 
the  use  of  firesafe  materials — those  which  cannot  start  to 
burn — is  recognized  as  one  of  the  biggest  aids  to  fire  preven¬ 
tion,  it  is  important  that  materials  like  concrete  and  stone 
be  used  whenever  possible. 

Resale  value  is  undoubtedly  enhanced  when  any  property 
is  equipped  with  good  buildings.  The  prospective  buyer  can 
afford  to  pay  more  for  such  property  because  upkeep  expenses 
on  buildings  will  be  negligible. 

Whether  the  new  building  is  a  roadside  market  or  a  farm 
home,  a  suburban  church  or  a  creamery  for  the  small  town, 
cobblestone  and  concrete  will  be  found  suitable.  There  are 
no  limitations  to  what  can  be  done  with  the  material  with 
proper  study  and  application. 


This  cobblestone  filling  station  was  built  by  the  owner  who  is  seen  standing  by  the  column 

in  the  foreground. 


Cobblestone  arches,  lintels  and  watertables  add  to  the  interest  and  beauty  of  this  bungalow. 


Building  with  Concrete 
and  Cobblestone 

In  the  rapidly  increasing  use  of  concrete  is  seen  a  determined  effort 
on  the  part  of  the  nation  to  decrease  its  fire  losses  which  now  amount 
to  more  than  half  a  billion  dollars  annually.  Appalling  though  this 
figure  is,  losses  are  not  confined  to  property  damage — more  than  14,000 
lives  are  snuffed  out  each  year  by  the  fire  demon.  Protection  against 
such  losses  can  and  is  being  obtained  by  construction  with  concrete, 
recognized  the  world  over  as  a  fireproofing  material  of  the  first  order. 

The  staggering  losses  by  fire  are  probably  exceeded  by  the  damages 
caused  by  the  agencies  of  rust  and  decay  which  each  year  cost  property 
owners  unbelievable  sums.  These,  too,  can  be  greatly  reduced  by  the 
use  of  concrete  construction  which  successfully  resists  the  destructive 
action  of  the  elements. 

Cobblestone  work,  employing  native  stone  and  concrete,  satisfies 
both  the  requirements  for  fire-safety  and  permanence.  Its  durability 
and  fire-safety  are  readily  recognized  from  common  knowledge  of  the 
materials  composing  its  structure.  Cobblestones  are  especially  durable, 
having  been  exposed  to  the  elements,  and,  therefore,  freed  of  all  softer 
materials.  The  enduring  qualities  of  concrete,  the  other  basic  material 
in  cobblestone  work,  are  well  known.  Combined,  these  two  produce  a 
lasting,  fire-resistive  type  of  construction. 

Practically  every  section  of  the  country  has  a  supply  of  stones  suitable 
for  cobblestone  work,  making  this  an  unusually  economical  type  of  con¬ 
struction.  Deposited  by  the  glaciers  or  as  the  remnants  of  erosion  such 
stones  are  generally  considered  of  little  value  and  often  are  a  detriment 
to  the  property.  Cobblestone  construction  affords  a  practical  means  of 
utilizing  this  material. 


Building  With  Concrete 


4 

Stones  Require  No  Special  Treatment 

The  stones  require  no  special  preparation  for  this  work;  sizes  and 
shapes  can  vary  within  wide  limits.  General  practice  favors  the  use 
of  medium  sized  stones  easily  grasped  in  one  hand;  large  units  are  cum¬ 
brous  to  handle  and  small  ones  slow  down  speed  of  construction.  Most 
builders  use  stones  as  they  find  them;  others  break  them  or  chip  the  faces 
according  to  the  effect  desired.  Fragments  from  stone  quarries  are  also 
utilized  in  cobblestone  construction. 

Colors  Blend  with  Nature 

The  wide  range  of  colors  and  textures  possible  in  cobblestone  work 
lends  it  beauty  and  interest.  Shades  of  color  in  stones  are  rarely  of  the 
brighter  hues,  the  subdued  colors  of  nature  predominating.  Unevenly 
weathered  faces,  varied  sizes  and  colors  of  stones,  and  the  irregular  mortar 
joints  characteristic  of  this  type  of  work,  all  help  to  make  cobblestone 
construction  harmonize  with  its  surroundings.  Chipping  often  reveals 
shades  of  color  not  visible  on  the  faces  of  the  stones  as  they  are  found. 
Sorting  of  the  stones  for  colorings  or  for  sizes  affords  unlimited  possi¬ 
bilities  for  varying  the  final  effect. 

For  the  agricultural  community  cobblestone  construction  is  especially 
useful.  Cobblestone,  sand  and  pebbles  needed  for  this  class  of  work  are 
often  found  near  the  building  site  and  can  be  obtained  for  the  cost  of 
hauling.  Portland  cement  is  obtained  from  the  nearby  supply  yard  as 
is  the  small  amount  of  lumber  needed  for  forms.  The  tools  required  are 
those  generally  used  on  the  farm.  No  man  need  hesitate  to  undertake 
the  work  on  account  of  inexperience.  For  example,  the  small  brooder 
house  shown  below  was  erected  by  a  man  who  had  no  previous  ex¬ 
perience  in  laying  cobblestone.  Best  results  are  obtained,  however, 
when  certain  building  practices  such  as  outlined  on  the  following  pages 
are  followed. 


and  Cobblestone 


5 

■  mi  in  1 1  in  1 1  tin  ii  mi  i  in  ■  ■  in  i  in  1 1 1 1  tin 


Cobblestones,  sand  and  pebbles  collected  preparatory  to  building  a  residence. 


Laying  Out  the  Foundation 

A  practical  method  of  laying  out  foundations  for  small  buildings  is 
illustrated  below.  A  base  line  marking  out  one  side  of  the  building, 
as  A-B,  is  established,  and  nails  are  driven  into  the  tops  of  the  stakes 
to  indicate  the  precise  locations  of  the  corners.  On  the  line  A-B  locate 
stake  F,  6  feet  from  A.  Stake  E  is  then  driven  10  feet  from  F  and  8  feet 
from  A.  Nails  are  also  driven  in  the  tops  of  stakes  E  and  F.  The  corner 
E-A-F  is  then  a  right  angle  triangle  with  sides  6,  8  and  10  feet  long.  Side 
A-E  extended  will  represent  the  side  A-D  of  the  building  and  the  point  D 
the  third  corner.  The  fourth  corner  C  is  located  in  a  similar  manner  by 
the  right  triangle  method.  Strings  are  then  stretched  over  the  corner 
stakes  and  carried  to  batter  boards  as  illustrated  (GH,  KL,  MN,  PR). 
The  outline  of  the  building  having  thus  been  determined,  the  corner 
stakes  are  removed  and  excavation  commenced,  either  for  trench  or 
complete  basement  as  the  occasion  demands. 


6  Building  With  Concrete 


Solid  Concrete  Foundations 

Footings  and  foundation  walls  for  cobblestone 
buildings  are  generally  made  of  solid  concrete,  usu¬ 
ally  spoken  of  by  builders  as  monolithic  concrete. 

This  type  of  foundation  is  easy  to  build  and  as¬ 
sures  that  the  wall  load  will  be  evenly  distributed 
on  the  soil,  insuring  against  settlement.  It  also 
provides  an  excellent  base  on  which  to  start  the 
cobblestone  wall. 

Dimensions  of  footings  vary  depending  upon 
the  size  and  weight  of  the  building.  Under  the 
walls  of  a  barn,  a  footing  2  feet  wide  and  12  inches 
deep  will  ordinarily  be  sufficient.  Residences  and 
filling  stations  require  footings  approximately 
18  inches  wide  and  12  inches  deep.  Footings 
12  inches  wide  and  8  inches  deep  will  serve  for  smaller  buildings  such  as 
one-car  garages,  poultry  houses  and  milk  houses.  Foundation  walls 
8  to  12  inches  thick  are  generally  ample  for  structures  of  this  type.  Cob¬ 
blestone  walls  are  rarely  made  less  than  8  inches  thick  and  accordingly 
must  have  at  least  8  inches  of  foundation  wall  to  rest  upon. 

For  buildings  without  basement  the  sides  of  the  foundation  trench 
can  be  used  for  forms  if  the  soil  is  of  a  type  that  does  not  cave  readily. 
If,  however,  the  earth  does  not  stand  by  itself,  forms  like  those  shown 

in  the  illustration  on 
page  7  will  be  required. 
In  either  case  forms  will 
be  required  for  con¬ 
structing  the  inner  wall 
(see  illustration  at  the 
left)  of  the  basement  un¬ 
less  that  part  of  the 
structure  is  built  of  cob¬ 
blestone. 

Forms  for 
Cobblestone  Work 

In  cobblestone  con¬ 
struction  above  grade, 
forms  are  required  for 
the  inner  wall  only,  no 
outer  forms  being  need¬ 
ed.  Two  methods  of 
building  inner  forms  are 
in  common  use.  In  one 
method,  used  mostly  for 


Forms  for  the  foundation  walls  where  the  embankment  serves 
as  the  outer  form.  This  type  of  form  is  used  for  building 
cobblestone  walls. 


Substantial  and  non-rotting 
corner  post  built  with  cob¬ 
blestone  found  on  the  farm. 


and  Cobblestone 


7 


smaller  jobs,  the  complete  inner  form 
is  built  before  masonry  work  is  started. 
In  the  other  method  the  wall  is  built  in 
courses,  the  sheathing  boards  against 
which  concrete  is  placed  being  raised 
and  used  again  and  again  until  the 
work  is  completed. 

Forms  for  either  method  are  simple 
in  construction.  Studs  used  for 
supporting  form  sheathing  consist  of 
2  by  4  or  2  by  6-inch  material  placed 
not  more  than  3  feet  apart  to  prevent 
any  bulging  in  the  finished  wall.  Studs 
should  be  rigidly  braced  with  diagonal 
struts  so  that  there  will  be  no  move¬ 
ment  of  the  forms  while  the  wall  is 
being  built. 


This  method  of  forming  is  used  for  the  foun¬ 
dation  when  the  soil  caves. 


Boards  having  straight  edges  and  surfaced  one  side  are  recommended 
for  form  sheathing.  The  sides  coming  in  contact  with  the  concrete  mixture 
should  be  oiled  or  greased  to  make  removal  easy.  Where  the  wall  is 
built  in  courses,  enough  boards  should  be  on  hand  to  permit  the  work  to 
proceed  without  interruption  yet  allowing  forms  to  remain  in  place  long 
enough  for  the  wrall  to  acquire  sufficient  strength  to  stand  by  itself.  Boards 

12  inches  or  more  wide 
are  preferable  to  nar¬ 
rower  boards  because 
they  permit  a  greater 
height  of  wall  to  be 
built  in  one  course.  Usu¬ 
ally  one  course  is  built 
each  day.  In  warm 
weather,  however,  the 
concrete  will  often  hard¬ 
en  quickly  enough  so 
that  the  forms  can  be 
raised  and  a  second 
course  built  during  the 
same  day. 

To  allow  forms  to  be 
taken  off  easily  and  with¬ 
out  disturbing  the  sup¬ 
ports  a  removable  strip  is 

Forms  must  be  true  and  plumb  and  properly  braced.  Note  USed  aS  backing  at  each 
I  by  3-inch  strips  between  form  boards  and  studs.  These  per-  .  i  i  •  .  i 

mit  form  boards  to  be  raised  without  disturbing  frame  work.  S tUQ,  3/S  SilO\V  II  III  LHC 


8  Building  With  Concrete 


Cobblestone  walls  completed  for  a  modern  poultry  house. 


drawing  on  page  7  and  in  the  illustrations  on  page  13.  Any  piece  of  lum¬ 
ber  two  or  three  feet  long,  usually  1  by  2  or  1  by  3-inch  material,  is  satis¬ 
factory.  These  strips  are  tacked  to  the  studs.  When  the  strips  are  removed, 
sheathing  boards  are  easily  taken  off  and  raised  without  displacing  the 
studs. 


Zk4'uprighh 

bo  full  wall 


I"x3>strips-U 


-•*! 'x / Z"  boards 


Mix  for  Concrete  Foundation 

The  concrete  mix  recommended  for  foundation  wall  construction  is 
5  gallons  of  water  per  sack  of  cement  to  which  such  amounts  of  moist 
sand  and  pebbles  are  added  as  will  produce  a  rather  thick  consistency. 
This  amount  of  water  is  decreased  to  gallons  if  the  sand  and  pebbles 

are  wet,  and  increased  to 
6V2  gallons  if  the  sand 
and  pebbles  are  thor¬ 
oughly  dry. 

Proportions  for  the 
first  trial  mix  are  1  part 
cement  to  parts  sand 
to  3)/£  parts  pebbles 
(l-2^-3  x/i  mix)  using 
pebbles  up  to  V/2  inches 
in  size.  It  may  be  found 
that  these  proportions 
give  too  stiff  a  mix,  too 
wet  a  mix  or  a  mix  that 
lacks  smoothness  and 
workability.  These  con¬ 
ditions  can  be  corrected 
by  changing  slightly  the 
proportions  of  sand  and 
pebbles.  Great  care  must 

Form  boards  have  been  raised  for  next  course.  Note  that  form  be  taken,  however,  not 
board  is  not  nailed  but  rests  on  a  block  tacked  to  the  side  of  .  _ .1 1  1 

the  stud.  to  use  more  than  the 


braces 


and  Cobblestone 


9 


amounts  of  water  mentioned  above, 
because  excess  mixing  water  will  re¬ 
sult  in  weak,  porous  concrete. 


Placing  Concrete  for  Foundation 

Concrete  should  be  placed  in  the 
forms  within  45  minutes  after  mixing. 

It  should  be  deposited  in  layers  of  uni¬ 
form  depth,  usually  not  exceeding  6 
inches.  When  placed  in  the  forms  it 
should  be  tamped  and  spaded  so  as  to 
cause  it  to  settle  thoroughly  every¬ 
where  in  the  forms  and  produce  a 
dense  mass.  By  “spading”  is  meant  the 
working  of  a  spade  or  chisel-edge  board 
in  the  concrete  and  between  it  and  the 
side  of  the  forms,  moving  the  spading 
tool  to  and  fro  and  up  and  down. 

This  working  of  the  concrete  next  to  the  forms  forces  the  large  pebbles 
or  stone  particles  away  from  the  form  face  into  the  mass  of  the  concrete 
and  insures  an  even,  dense  surface  when  forms  are  removed. 

Smooth  off  the  top  of  the  foundation  with  shovel  or  trowel  to  provide 
a  level  base  for  the  cobblestone  wall.  The  foundation  should  be  given 
at  least  one  day  to  harden  before  starting  the  cobblestone  work. 


An  elevated  water  storage  tank  with  room  for 
general  storage  purposes  on  the  ground  level. 


Mix  for  Wall 

The  cobblestone  wall  is  laid  up  in  a  mixture  of  concrete  which  is  placed 
with  trowel  or  shovel,  preferably  both  for  speedy  work.  The  concrete 


Rural  school  buildings  constructed  with  concrete  and  cobblestone  are  strong,  durable  and  rotproof. 

Walls  can  be  constructed  rapidly. 


10  Building  With  Concrete 

. . . . . . . 


A  good  concrete  mixture  will  Mixing  board,  box  for  measuring  sand  and  pebbles,  pail  for 
have  this  appearance.  measuring  water,  shovel  and  wheelbarrow  used  in  building 

with  concrete  and  cobblestone. 


mixture  should  be  of  such  consistency  as  will  permit  of  rapid  construction. 
A  little  experience  will  enable  the  builder  to  determine  the  best  degree  of 
plasticity. 

The  recommended  concrete  mix  for  this  work  is  434  gallons  of  water 
per  sack  of  cement,  with  sand  and  pebbles  in  moist  condition.  If  the 
sand  and  pebbles  are  dry,  use  534  gallons  of  water,  and  if  dripping  ivet 
cut  down  the  quantity  to  3%  gallons.  Less  water  is  specified  when  aggre¬ 
gates  are  in  a  moist  condition  because  the  moisture  in  the  sand  and  pebbles 
is  free  to  act  upon  the  cement. 

For  the  first  or  trial  batch  a  mixture  containing  one  sack  of  cement, 
234  cubic  feet  of  sand  and  2 34  cubic  feet  of  pebbles  (1-234*234  mix)  is 
recommended,  using  pebbles  up  to  one  inch  in  size.  It  may  be 

necessary  to  change  the  proportions  of 
sand  and  pebbles  somewhat  to  get  the 
right  degree  of  workability.  If  the  above 
proportions  give  a  mix  which  is  too 
sloppy  increase  the  amounts  of  sand 
and  pebbles;  if  too  dry  cut  down  the 
amounts  in  the  next  batch.  The  size  of  the 
aggregate  is  limited  to  one  inch  as  larger 
pebbles  might  result  in  faulty  mortar  joints 
between  the  stones.  Do  not  change  the 
recommended  amount  of  water  per  sack  of 
cement. 

Mix  Thoroughly 

Concrete  can  be  mixed  by  machine  or  by 
hand.  In  either  case  mixing  must  proceed 
until  stones  or  pebbles  are  completely 
coated  with  a  mortar  of  sand  and  cement. 
For  cobblestone  construction  the  quanti¬ 
ties  of  mortar  needed  are  not  excessive 
and  hand  mixing  will  probably  be  found 
satisfactory,  particularly  on  small  jobs 


and  Cobblestone 


11 


where  only  one  man  is  laying  the 
stones.  Where  two  or  more  men  are 
at  work  it  will  usually  pay  to  have  a 
small  mechanical  mixer.  A  machine 
mixer  will  be  found  especially  useful 
in  mixing  concrete  for  footings  and 
foundation  wall.  Mixing  should  con¬ 
tinue  for  a  minute  and  a  half  after  all 
materials  including  water  have  been 
placed  in  the  mixer  drum. 

In  hand  mixing  a  platform  not 
smaller  than  8  feet  by  12  feet  with 
tight  joints  and  smooth  surface  is  used. 

A  2  by  2-inch  piece  or  similar  strip  should  be  nailed  around  the  outer 
edge  to  prevent  waste  of  materials  during  mixing. 

Mixing  by  Hand 

The  method  of  mixing  generally  used  is  as  follows: 

Spread  out  the  measured  amount  of  sand  on  the  platform;  distribute 
the  required  quantity  of  cement  evenly  on  top  of  the  sand,  and  mix  them 
with  a  square  pointed  shovel  until  the  mixture  is  uniform  in  color.  On 
the  cement-sand  mixture  spread  the  measured  amount  of  pebbles  and 
mix  thoroughly  as  before  by  turning  with  the  shovel  until  the  mass  is  of 
the  same  even  color  throughout.  The  center  of  the  pile  is  then  scooped 
out  and  the  measured  amount  of  w7ater  poured  slowly  into  the  depression 
thus  formed,  the  materials  in  the  pile  being  gradually  turned  into  the 


Steps  in  the  work  of  mixing  concrete  by  hand.  Thorough  mixing  is  necessary  for  best  results. 


Precast  concrete  units  and  concrete  brick  are 
used  here  to  form  sharp  true  corners. 


12 


Building  With  Concrete 


Gauging  thickness  of  wall.  Trowel  is  used  to  Rocks  should  not  be  jammed  against  the  form 
measure  distance  from  face  of  form  to  outer  face  board.  An  appreciable  amount  of  mortar  should 
of  wall.  be  between  stone  and  form. 


water  with  shovels  and  gradually  mixed  until  the  cement,  sand  and  pebbles 
have  been  thoroughly  and  uniformly  combined  and  the  mixture  has  the 
same  color  and  plasticity  throughout. 

Building  the  Wall 

In  preparing  materials  for  cobblestone  construction  the  supply  of 
stones  is  sorted,  laying  aside  those  of  a  suitable  size,  color  and  shape  for 
the  wall  and  dropping  rejected  pieces  in  the  mixture  when  placing  con¬ 
crete  for  footing  and  foundation  walls.  Always  make  certain  that  the 
stones  are  completely  covered  with  the  concrete  mixture.  The  appear¬ 
ance  of  the  wall  can  be  varied  to  suit  the  owner  depending  only  on  the 
variety  of  materials  at  hand.  A  rough  wall  can  be  made  using  rocks  of 
irregular  and  jagged  surfaces  or  a  smooth  wall  can  be  obtained  by  select¬ 
ing  stones  having  flat  or  rounded  surfaces.  Further  variation  in  effect  is 
obtained  by  pointing  with  plain  or  colored  mortar. 


Placing  mortar  on  wall.  Use  shovel  to  deposit  Spading  mortar  with  trowel  to  insure  that  all 
mortar  for  speedy  construction.  spaces  between  stone  will  be  completely  filled. 


and  Cobblestone 


13 


Tamping  concrete.  Use  short  broom  handle  Raking  out  the  joints.  After  mortar  has  hardened 
or  other  tamper  to  insure  compact  concrete,  somewhat  the  surplus  is  raked  off  face  of  stone 

and  the  joint  pointed.  Pointing  should  not  be 
done  when  mortar  is  too  green. 


As  each  stone  is  laid  it  is  lightly  tamped  into  place  and  all  crevices 
between  stones  filled  with  concrete.  Each  stone  must  be  carefully  bed¬ 
ded  in  the  mortar.  Concrete  between  stones  and  against  the  form  face 
is  spaded  and  tamped  as  it  is  placed  to  insure  compactness  and  a  smooth 
inner  surface  when  forms  are  removed. 

To  insure  a  definite  minimum  thickness  of  concrete  on  the  inner  side 
of  the  cobblestone  wall  the  handle  of  the  trowel  may  be  used  as  a  gauge 
and  none  of  the  stones  placed  closer  to  the  wood  forms  than  the  thickness 
of  the  trowel  handle.  The  wall  thickness  is  easily  kept  uniform,  a  simple 
method  being  to  measure  the  distance  with  the  trowel.  Both  methods 
are  shown  in  the  illustrations  on  page  12. 


Showing  strip  behind  form.  Note  projecting  Removing  strip.  Projecting  nail  has  been  pulled, 
nail  in  1  bv  3  which  can  be  readily  with-  allowing  strip  to  be  removed.  This  allows  the 
drawn  thus  allowing  strip  to  be  removed.  form  to  be  taken  off  and  raised  without  disturb¬ 
ing  the  uprights  or  studs. 


14 


Building  With  Concrete 


Exterior  Finishes 


In  general  there  are  two  ways  of 
finishing  the  outer  face  of  the  cobble¬ 
stone  wall.  These  two  methods  are 
commonly  known  as  “pointed”  and 
“unpointed”  work.  In  the  latter, 
surplus  mortar  is  raked  out  with  the 
trowel,  practically  no  mortar  being 
visible  in  the  finished  wall. 


In  pointed  work  a  special  mortar 
for  filling  crevises  between  stones 
serves  to  seal  the  joints  and  produce 
a  more  finished  appearance.  Mix  one 
part  cement  with  three  parts  sand  for 
best  results  with  such  mortar,  no  lime 
being  required.  Mineral  coloring  ma¬ 
terials,  finely  ground  and  thoroughly 
distributed  in  the  mortar,  may  be  used 

to  produce  colored  joints.  The  amount  c  ,  ,  ,  .  , 

A  .  _  rrames  tor  door  and  window  openings  must 

of  coloring  matter  used  must  be  only  be  rigidly  braced  in  place.  Note  the  appearance 

,  .  l  .  *  .  l  •  1  ,  from  inside  ot  this  cobblestone  creamery. 

enough  to  secure  the  tint  desired,  exact 

amounts  for  various  tints  being  determined  by  experiment  or  trial. 


Section  through  finished  wall.  Note  how  closelv 
the  concrete  and  stone  are  bonded  together  and 
the  smooth  surface  obtained  on  the  inner  wall. 


Where  concrete  floors  are  desired 
they  are  generally  built  after  the  walls 
are  completed.  If  the  soil  on  which 
the  floor  is  laid  is  well  drained  the 
concrete  can  be  placed  directly  on  it 
after  all  refuse,  grass  roots  and  similar 
materials  have  been  removed  and  the 
ground  has  been  leveled  off  and  well 
compacted.  If  drainage  is  poor  and 
soil  water  is  likely  to  be  present  a  six- 
inch  fill  of  cinders  or  gravel,  well  com¬ 
pacted,  is  recommended. 

The  floor  slab  should  preferably  be 
placed  in  strips  four  or  five  feet  wide 
and  at  least  four  inches  in  thickness, 
using  the  same  mixture  of  concrete 
throughout.  This  is  known  as  one- 
course  construction.  The  forms  used 
for  separating  the  area  into  sections, 
usually  2  by  4’s  set  on  edge  and  held 
in  place  by  stakes,  also  provide 
a  guide  for  leveling  off  the  concrete 


and  Cobblestone  15 

MiiiiiiiiiiiiiiiiMiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiMiMiiMiiiiHiniiHiiiiiiiiiiiMiiiHiiiiiiiiiiiiniiiiniiiiiMiMiiiiiiitiniiniMiiiiiiniiiiiiMiiniiiiiniiiiiiiiiiiiiiiniiiiiiiiiniiiiiiniiiiniiiiiiiiiiiiiiiiHiniiiiniiiimiiiniiiiiinmiMiiiiii 


at  the  desired  slope  or  level.  This  is  done  by  means  of  a  straight  edge 
(a  1  by  6-inch  board  is  satisfactory)  resting  on  the  forms  as  a  guide. 
After  concrete  has  hardened  somewhat,  but  is  still  workable,  the  surface 
is  compacted  and  worked  with  a  wooden  float  to  give  it  an  even  surface. 
Too  much  troweling  is  to  be  avoided.  Short  pieces  of  plank  are  sometimes 
used  by  the  finisher  to  kneel  on  in  working  over  the  fresh  concrete. 

Other  Construction  Details 

Window  and  door  openings  are  provided  with  sills  and  lintels  as  in 
any  other  type  of  masonry  construction.  Frames  for  doors  and  windows 
using  either  plank  or  box  frames  as  required  are  set  in  place  and  braced 
before  the  wall  is  built,  with  bolts  or  spikes  projecting  into  the  wall  to 
provide  anchorage.  Good  practice  includes  priming  of  these  frames 
before  they  are  used.  The  plate  for  the  roof  is  securely  anchored  into  the 
cobblestone  wall  by  means  of  bolts  placed  in  the  top  course  of  the  wall  as  laid 

Cttring 

If  cobblestone  walls  are  exposed  to  sun  and  wind  before  hardening, 
much  of  the  water  necessary  to  curing  will  evaporate  and  the  concrete 
will  simply  dry  out.  This  condition  may  occur  when  forms  are  moved 
up  as  the  wall  is  built.  To  keep  the  wall  moist  and  to  guard  it  against 
rapid  evaporation  under  these  conditions,  moist  canvas  or  burlap  covering 
is  placed  over  the  wall.  This  material  is  kept  moist  during  the  early 
hardening  period  or  approximately  ten  days. 

Floors  are  cured  by  covering  with  earth  or  sand  as  soon  as  concrete 
has  hardened  sufficiently  to  prevent  damage  to  the  surface.  This  cover¬ 
ing  is  kept  moist  for  10  days  by  sprinkling.  At  the  end  of  this  time  the 
floor  can  be  put  into  service. 


Cobblestone  construction  not  only  proved  economical  but  added  beauty  and  strength  to  the  design 
of  this  firesafe  filling  station  and  roadside  hotel. 


Cutting  Costs l 

In  countless  ways  concrete  can  help  you  cut  costs,  be¬ 
cause  it  is  permanent,  firesafe  and  sanitary — therefore 
economical. 

By  starting  now  to  use  concrete  for  new  structures  and 
repairs  you  can  gradually  cut  your  costs — increasing  your 
profits. 

Check  below  the  subjects  upon  which  you  want  definite 
information  and  mail  the  coupon.  Free  booklets  will  be 
sent  immediately. 


PORTLAND  CEMENT  ASSOCIATION 

A  National  Organization  to  Improve  and  Extend 
the  Uses  of  Concrete 


District  Offices  at 


Atlanta 

Birmingham 

Boston 

Chicago 

Columbus,  O. 

Dallas 


Denver 
Des  Moines 
Detroit 

Helena,  Mont. 
Indianapolis 
Jacksonville 
Kansas  City 


Lincoln,  Nebr. 
Los  Angeles 
Milwaukee 
Minneapolis 
Nashville 
New  Orleans 


New  York 
Oklahoma  City 
Parkersburg 
Philadelphia 
Pittsburgh 
Portland,  Oreg. 
Richmond,  Va. 


Salt  Lake  City 
San  Francisco 
Seattle 
St.  Louis 

Vancouver,  B.  C. 
Washington,  D.  C. 


PORTLAND  CEMENT  ASSOCIATION 
(Address  office  nearest  you) 

Please  send  me  free  information  on: 


□  Barns 

□  Barn  floors 

□  Basement 

□  Cisterns 

□  Feeding  floors 


□  Fence  posts 
[3]  Floors 

□  Foundations 

□  Garages 

□  Houses 


□  Septic  tanks 

□  Sidewalks 

□  Silos 

□  Troughs 

J  Water  supply  tanks 


Name . 

Street  No. 

or  R.  F.  D . 

City . State. 


Printed  in  U.  S.  A. 


F  19 — 25M — 3-28 — 8 — 16P 


